Flying model airplanes, such as of the type utilizing rubber bands as the source of power for propulsion, generally consist of an airframe having a geometrical arrangement to produce lift, typically including a central body, wings and a tail. To ensure longitudinal stability, most planes employ tails which are approximately one third the area of the wings, contain long noses to compensate for the weight of the engine, and provide wings that slope upwards from root to tip.
Because the craft is powered by rubber, which inherently has potentially less endurance in flight than an internal combustion engine, it is necessary to extend the available power over as long a period of time as possible. Wide blades are sometimes used to absorb and slow the unwinding of the tightly wound rubber. Other prior art crafts have implemented a plurality of rubber bands to increase and prolong power.
For example, U.S. Pat. No. 1,682,267 to Daniel is directed to a toy airplane having two rubber bands suspended at opposite sides of the longitudinal center of the body of the toy. The endless elastic bands are suspended at one end from hooks attached to the rear ends of driven shafts. The bands are suspended at the other end from hooks attached to the front ends of power shafts, which contain pinions and a gear wheel. A crank is turned to twist the rubber bands which store the power to operate the driving shafts and gears so as to rotate the propeller shaft and the air propeller.
U.S. Pat. No. 1,936,072 to Roderick similarly provides a plurality of rubber bands to power a model aircraft. Two driving units operate successively to double the period of time of motor operation.
Other similar free-flying rubber band powered toy airplanes are disclosed in U.S. Pat. No. 1,365,917 to Hutchinson, U.S. Pat. No. 2,098,019 to Weimerskirch, and U.S. Pat. No. 4,318,455 to Lapierre.
All of these devices are subject to the inherent flaws of the longitudinally positioned twisted rubber band: imbalance and unpredictability.